Question

Heart Rates For a certain group of individuals, the average heart rate is 74 beats per minute. Assume the variable is normally distributed and the standarddeviation is 2 beats per minute. If a subject is selected at random, find the probability that the person has the following heart rate. Use a graphing calculator.Round the answers to four decimal places.Higher than 73 beats per minute,P (x> 73) =

Answer 1

we need to determine P (x> 73)

when

mean: μ = 74 beats/min

standard deviation: σ = 2 beats/min

First we need to use the following formula:

$z=\frac{x-\mu}{\sigma}$

where

x = 73

μ = 74

σ = 2

and

Z is the z-score

... therefore

$z=\frac{73-74}{2}=-\frac{1}{2}=-0.5$

If we check a table of z scores, we will find that when z = -0.5, then P = 0.3085

Now, since we need P(x>73)

therefore

$P=1-0.3085=0.6915$

P(x>73) = 0.6915